Download or read book Using Steady state Vibrational Spectroscopy to Characterize the Effect that Molecular Environments Have on the Kinetics of Chemical Systems written by Andrea Giordano and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A goal that unifies all chemists is the desire to understand the intermolecular and intramolecular interactions that occur in a given system. For many chemical systems, we have an understanding of the intramolecular interactions that occur within a molecule, and how these interactions dictate the physical properties of the molecule, such as the dipole moment, color, or the dielectric constant. The intermolecular interactions that occur between molecules and their molecular environment have proven to be more difficult to isolate, due to multiple interactions occurring simultaneously. It is important to understand these interactions between molecules and their molecular environment because such interactions affect nearly every practical chemical system, from biological to industrial applications. Therefore, it is of the upmost importance to understand how the intermolecular interactions can manifest throughout chemical systems. We are interested in separating the multiple contributions to the intermolecular interactions that arise from the molecular environment. To achieve this goal, I developed theoretical and experimental frameworks for determining kinetic parameters of chemical systems using steady-state vibrational spectroscopy, a tool that has proven very powerful for determining the effects of both intramolecular and intermolecular interactions, therefore, we have chosen to focus on using vibrational spectroscopy in my dissertation. I first demonstrate the equivalency between the kinetic information extracted from IR and Raman spectroscopies by obtaining identical activation energies for the ligand site exchange of Fe(CO)3([eta]4-norbornadiene) (FeNBD). These experiments rely upon the extraction of kinetic information from steady-state band shapes and demonstrated that either vibrational spectroscopic technique can be used to extract kinetic information from the band shapes of steady-state spectra. In order to do this, I worked with collaborators to extend the theoretical framework for extracting the rate constant from the band shapes of vibrational spectra to include Raman spectroscopy. The next step towards the goal of separating the multiple contributions to the intermolecular interactions is to categorize these contributions as static effects and dynamic effects. For the purpose of this work, I define static effects as those that arise from solute-solvent interactions that cause changes in the band shape, while dynamic effects are those that arise from changes in the dynamics of a system as a result of interaction with the molecular environment. I establish a way to separate static effects from dynamic effects by analyzing the solvent effects of Fe(CO)3([eta]4-cyclooctatetraene) using solvent-dependent IR spectroscopy. The dynamic effects induced by the solvent environment were analyzed through temperature-dependent Raman experiments of FeNBD in a series of linear alkane solvents. The last part of this dissertation further focused on the consequences of static effects, examining the morphology of conducting polymer films used in thin film devices. We used Raman spectroscopy to characterize the crystallinity of conducting polymer films with and without dopant materials. From this data, we constructed structure-function relationships by correlating the morphology of the polymer film to the overall device performance that will aid in the rational design of materials used in thin film devices. This part of my dissertation was done in collaboration with Prof. Elizabeth von Hauff at The University of Freiburg in Germany. Future experiments will explore the effects confining environments will have on the dynamics of FeNBD. Initial experiments to encapsulated FeNBD into a porous polymer matrix were successful, but there are many potential experiments along this line of reasoning that could be explored, and are discussed in the final chapter of this dissertation. In its entirety, this dissertation will provide the scientific community with a novel approach that combines the ability to measure ground state kinetics using steady-state vibrational spectroscopy with a theoretical framework to analyze the effects the molecular environment induces on the ground state kinetics in chemical systems.

Download or read book Inventory of Federal Energy related Environment and Safety Research for written by and published by . This book was released on 1980 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Inventory of Federal Energy related Environment and Safety Research for FY 1979 written by and published by . This book was released on 1980 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Topics in Chemistry written by Dr. A.Abdul Jameel and published by Vandana Publications. This book was released on with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: While searching the syllabi for the spectral aspects of Inorganic compounds and metal complexes, we come across some important chapters in chemistry in almost all Universities in India and abroad. Laser Raman spectroscopy, Supramolecular chemistry, Nanochemistry and Sonochemistry are found either as separate papers or as chapters in a paper in B.Sc., M.Sc. and M.Phil. syllabi. So we thought of including these chapters along with the inorganic aspects of spectroscopy like Nuclear Quadrupole spectroscopy, ORD and CD of Inorganic compounds, Mass spectra of inorganic compounds and Photoelectron spectroscopy. The limited knowledge of Laser chemistry and Raman spectroscopy leads to the less understanding of Laser Raman spectroscopy. Hence chapters on Laser chemistry and Fundamentals of Raman spectroscopy are included in this book. These chapters were once considered as specialization in chemistry but due to advancement in chemistry, they find place in the regular curriculum. The book is written in a simple language with more advanced and latest informations. Diagrams and tables are given for the better understanding of the subject matter. The book provides a comprehensive and indepth coverage of the subject. There is a shortage of suitable text books for these chapters and this book may fill the gap and will mostly be useful to all the B.Sc. and M.Sc. students and M.Phil. Scholars globally. This book is an outcome of very long teaching and research experience of the authors in the field of Inorganic chemistry. Apart from the subject study, this book may also be used for writing the competitive examinations like UGC–NET, Civil Services Examination and so on. This book is also useful for the interdisciplinary students studying physics and biological sciences.

Download or read book Spectroscopic Techniques for Polymer Characterization written by Yukihiro Ozaki and published by John Wiley & Sons. This book was released on 2022-03-14 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: An insightful exploration of cutting-edge spectroscopic techniques in polymer characterization In Spectroscopic Techniques for Polymer Characterization: Methods, Instrumentation, Applications, a team of distinguished chemists delivers a comprehensive exploration of the vast potential of spectroscopic characterization techniques in polymer research. The book offers a concise outline of the principles, advantages, instrumentation, experimental techniques, and noteworthy applications of cutting-edge spectroscopy. Covering a wide range of polymers, from nylon to complex polymeric nanocomposites, the author presents recent developments in polymer science to polymer, analytical, and material chemists, assisting them in keeping track of the progress in modern spectroscopy. Spectroscopic Techniques for Polymer Characterization contains contributions from pioneers in modern spectroscopic techniques from around the world. The included materials bridge the gap between spectroscopists, polymer scientists, and engineers in academia and industry. The book also offers: A thorough introduction to the progress in spectroscopic techniques, including polymer spectroscopy and near-infrared spectroscopy Comprehensive explorations of topical polymers studied by spectroscopy, including polymer thin films, fluoropolymers, polymer solutions, conductive polymers Practical discussions of infrared imaging, near-infrared imaging, two-dimensional correlation spectroscopy, and far-ultraviolet spectroscopy In-depth examinations of spectroscopic studies of weak hydrogen bonding in polymers Spectroscopic Techniques for Polymer Characterization: Methods, Instrumentation, Applications is a must-read reference for polymer, analytical, and physical chemists, as well as materials scientists and spectroscopists seeking a one-stop resource for polymer characterization using spectroscopic analyses.

Download or read book Vibrational Spectroscopy of Molecules on Surfaces written by Theodore E. Madey and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: The observation of the vibrational spectra of adsorbed species provides one of the most incisive methods for und erst an ding chemical and physical phenomena on surfaces. At the present time, many approaches may be applied to studies of molecular vibrations on surfaces. Some of these are used on high-area solids of technological importance (e.g., heterogeneous catalysts) while others are applied to single-crystal substrates to gain better understanding under conditions of controlled surface structure. This book has attempted to bring together in one place a discussion of the major methods used to measure vibrational spectra of surface species. The emphasis is on basic concepts and experimental methods rather than a current survey of the extensive literature in this field. Two introductory chapters describe the basic theoretical aspects of vibrational spectroscopy on surfaces, dealing with normal modes and excitation mechanisms in vibrational spectroscopy. The remaining seven chapters deal with various methods employed to observe surface vibra tions. These are arranged in an order that first treats the use of various methods on surfaces that are not of the single-crystal type. It is in this area that the field first got started in the late 1940s with pioneering work by Terenin and others in the Soviet Union, and by Eisehens and others in the United States in the 1950s. The last four chapters deal with relatively recent methods that permit vibrational studies to be made on single crystal substrates.

Download or read book Understanding Vibrational Spectroscopy in Complex Environments Through First Principles Modeling written by Jeffrey Becca and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Vibrational spectroscopy takes many forms, from techniques like Raman scattering to sum frequency generation. These techniques involve measuring the energy difference between the incident light and scattered light. Vibrational spectroscopy has the advantage that virtually any system can scatter light, while techniques like fluorescence spectroscopy that requires a molecule to be able to absorb and emit light. The main disadvantage of Raman spectroscopy is that the intensity of the process is much weaker than that of absorption and emission processes like fluorescence. In recent times, vibrational techniques have been paired with strong electric fields created by plasmonic resonances from metal surfaces and nanoparticles. These techniques are known as surface enhanced spectroscopy. Surface enhanced Raman scattering (SERS) has been used to study processes that are far too weak for normal Raman scattering, such as single molecule detection. While the pairing of plasmonic systems with Raman and other vibrational spectroscopies has been fruitful, the surface-enhanced techniques add complexity to understanding and simulating the resulting vibrational spectroscopy. Ideally, simulations would be capable of modeling the molecular species, the plasmonic metal system, and any solvent that may be in the experimental setup. Even for relatively quick first principles techniques like Density Functional Theory (DFT), systems of this size are far too great to simulate in any reasonable time frame. One way of overcoming this limit is to model the most important features of the system, usually the molecular target, with first principle techniques while including the relevant environmental effects with more approximate methods. However, careful consideration must be given to which environment effects are included into the simulations and what approximations are used. In SERS and other similar surface-enhanced techniques, the largest enhancement comes from the strong electric fields created from the plasmonic metals in which the molecule resides. While correctly modeling the intensity of the local electric fields is important to SERS, spectral changes often occur in surface-enhanced techniques due to other factors. These spectral changes occur because the molecule's electronic structure is not isolated from its environment. Adsorption to a surface or specific interactions with solvent often alter the electronic structure of the molecule enough that the resulting spectra is no longer the same as normal Raman scattering. This means that if the metal surface or solvent plays a significant role in experiment and it is not accounted for in an accurate enough manor, the resulting simulated spectra will not be correct. For these reasons, understanding which processes are important to the chemical species is a strong desire for the surface-enhanced spectroscopy community. In this work, various systems were simulated using different methods, which depended on the complexity required and the environmental effects that were included. First, doubly resonant infrared-visible sum frequency generation (DR-IVSFG) was simulated for a push-pull azobenzene compound. We show through our work that by tuning the visible laser, different spectral bands are selected and track along with the changing energy. This result was found by modeling two confirmations of the azobenzene compound with vibronic effects included through a Herzberg-Teller term. The resulting tracking nature was due to probing two different states in different confirmations of azobenze on the film, a low energy tracking of the \emph{cis} isomer and high energy tracking of the \emph{trans} isomer. Second, this work demonstrates how, combined with experiment, new surface enhanced Raman spectroscopy (SERS) ligands can be profiled. A group of different N-heterocyclic carbenes were simulated which elucidated binding characteristics and SERS spectral signatures. We demonstrated that using time-dependent density functional theory to simulate a Au20 nanocluster and carbene system could reproduce experimental SERS spectra. We also showed that the binding interaction of the carbene and the gold cluster is relatively strong, since the stable Au20 structure was perturbed enough by the carbene to raise an atom from the surface in an adatom-like configuration. Our simulations also showed agreement with experiment throughout various deuterated carbenes, with some deuterated species emphasizing the functional group contribution to the SERS spectra. In the next chapter, we continued the N-heterocyclic carbene studies in order to simulate the functionalization of carbene ligands already attached to the surface. We showed proof of modifying a NO$_2$ group to a NH$_2$ and ND$_2$ group depending on the reaction conditions, which was confirmed by experimental SERS measurements. This work also discusses the implementation of a Discrete Interaction Model / Quantum Mechanics (DIM/QM) method that includes explicit solvent molecules in SERS simulations. This implementation was used to study the effects that solvent has on the image and local electric fields near a pyridine molecule in a solvated nanoparticle junction, and an observation about how those fields change from normal Raman scattering and SERS in solution. We observed that for normal Raman scattering in solution, the solvent molecules had an overall screening effect, lowering the intensity of the Raman spectra. However, solution phase SERS shows an enhancement that does not exist without the solvent. This enhancement comes from increasing the near field generated by the plasmonic nanoparticle junction, leading to more intense and inhomogeneous electric fields. We also show that the SERS enhancement that arises from the solvent is large enough to rival the enhancement seen from the chemical enhancement mechanism and should be accounted for in simulations. By understanding these different ways that spectral signals can be altered by molecular interactions with their environment, this work has built a foundation of better understanding surface enhanced spectroscopies.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Publications written by United States. National Bureau of Standards and published by . This book was released on 1986 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biomedical Index to PHS supported Research written by and published by . This book was released on 1989 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1989 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vibrational Spectroscopy of Solids written by Peter Miles Anson Sherwood and published by CUP Archive. This book was released on 1972-09-21 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 1972 monograph is devoted to the analysis and interpretation of the infrared and Raman spectra of solid compounds, frequently used for their identification and characterization. It was thought unsatisfactory to analyse such spectra by the theory applicable to gas-phase samples, though this was frequently done. Furthermore, the results obtained by far infrared and laser Raman spectrometers, which detect the movement of atoms and/or molecules as a whole, had no gas-phase analogy. A separate approach to solid state vibrational spectra was therefore proposed within this volume. Dr Sherwood describes the solid state physics of vibrational spectroscopy and extends it to the more complex structures of low symmetry. He assumes an understanding of the infrared and Raman spectra of gases.

Download or read book Chemical Research Faculties written by American Chemical Society and published by . This book was released on 1988 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: